摘要: Gene therapy has undergone a remarkable development in the last 20 years. Particularly important advances have been made improvement of gene transfer and expression technology, with current efforts focusing on design safer long-term vectors as well systems possessing cell-type specificity for transgene delivery regulat‐ ability its by small molecules. The foreign genetic material can be administered vivo, ex vivo or vitro depending nature disease. A successful system must perform several functions. In all cases, therapeutic first delivered across cell membrane, which is significant barrier. Once inside cell, may exist episomally integrated into host genome vector. Moreover, an issue replication segregation during division order to maintain long-lasting expression. These specifications will discussed each along chapter.